If 你 want to know how to be Luigi I will tell you. First 你 finish the game than 你 go to to the 个人资料 menu and 你 hold l and R as 你 open 你 个人资料 and 你 will see Luigi. If 你 save when 你 play as Luigi it won't work so 你 have keep on holding l and R everytime 你 want to be Luigi and to be Mario just do not hold l and R just do what 你 always do just go on. I hope this works for 你 because it works for me. THIS IS ONLY FOR NEW SUPER MARIO BROS AND NEW SUPER MARIO BROS 2 NOT ANY OTHER GAME.